According to MS-SMB2 3.2.55 validate_negotiate request must
always be signed. Some Windows can fail the request if you send it unsigned
See kernel bugzilla bug 197311
CC: Stable <stable@vger.kernel.org>
Acked-by: Ronnie Sahlberg <lsahlber.redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
        } else
                iov[0].iov_len = get_rfc1002_length(req) + 4;
 
+       /* validate negotiate request must be signed - see MS-SMB2 3.2.5.5 */
+       if (opcode == FSCTL_VALIDATE_NEGOTIATE_INFO)
+               req->hdr.sync_hdr.Flags |= SMB2_FLAGS_SIGNED;
 
        rc = SendReceive2(xid, ses, iov, n_iov, &resp_buftype, flags, &rsp_iov);
        cifs_small_buf_release(req);